"Surveys will be undertaken in the Sea of Oman and in Lorestan Province in western Iran," Mahmoud Hajian was quoted as saying by Shana.
NIOC’s exploration department has carried out the first phase of its studies and discovered huge shale reserves in the Sea of Oman and in Lorestan with the help of domestic databases and geological surveys.
"The second phase is aimed at identifying the exact location of the reservoirs and estimating the volume of in-place reserves," he said, adding that studies could last four years, Financial Tribune reported.
Drilling operations will commence after the results of the second phase are reported.
Referring to shale gas deposits in Lorestan, he said one exploration block is located in the Zagros Mountain range near Qali Kouh Mountain.
Energy experts, including Jafar Tofiqi, the head of the Oil Ministry Research Institute, say the abundance of conventional oil resources means the shale agenda is unlikely to move beyond exploration and discovery, without any serious plan for production.
Producing conventional crude in the oil-rich Persian Gulf region costs between $15 and $25 a barrel as opposed to $40-80 for shale oil.
Massive shale reserves have already been confirmed in Iran’s Zagros basin and near Aligoudarz city in Lorestan.
In July 2015 IRNA quoted an unnamed source as saying preliminary explorations have found three or four oil shale basins with signs of kerogen, a waxy, insoluble organic substance that forms when organic shale is buried under several layers of sediment, in Kerman and Semnan provinces.